混合溶剂诱导PS膜的去润湿过程

Mixed Solvent Induced Dewetting of Polystyrene Thin Film

采用光学显微镜及原子力显微镜等实验手段研究了聚苯乙烯(PS)膜在水和丙酮混合溶剂诱导下的去润湿过程.实验发现,在亲水基底上,随着丙酮含量的减少,在整个去润湿过程中孔半径与时间呈e指数关系[R～exp(t/τ)],然后呈线性关系(R～t),最后为R～t0.76,并且孔增长机理从成核增长机理转变为取代机理.在疏水基底上,随着丙酮含量的减少,在整个去润湿过程中孔半径与时间呈e指数关系[R～exp(t/τ)],然后呈线性关系(R～t),最后为R～t0.72,孔增长的机理未发生变化.对相同膜厚的高分子薄膜,无论在亲水基底还是疏水基底上,高分子薄膜的滑移效应随着丙酮含量的减少而变化,且在疏水基底上丙酮含量的减少对孔增长动力学的影响比在亲水基底上的影响更大.

We investigated the dewetting process of PS film induced by mixed solvent of water and acetone with the method of OM and AFM.By changing the proportion between acetone and water in the mixed solvent,it was found that on the hydrophilic substrate,with the decreasing of volume fraction of acetone,first R-exp（t/τ）,then R-t,and at last R-t0.76.Besides,when the volume fraction of acetone in mixed solvent further decreased,the dewetting mechanism changed from nucleation and growth to penetration-replacement.While on hydrophobic substrate,first R-exp（t/τ）,then R-t,at last R-t0.72,and the mechanism of hole growth was still nucleation and growth mechanism.But the slippage effect of PS was valid on both hydrophilic substrate and hydrophobic substrate.